Trying to resolve it caused a mini tank crash (all snails and fish belly up). However - in the re-stocking and nutrient control/export came my solution. I measured silicates and there were some in the water, not huge amounts, but enough to give a reading on the test kit. 0.1ppm. As silicate is directly tied to phosphate and my po4 was almost 0 I decided to shove some rowaphos (double the recommended dose for me, worked almost in week) in my filter. It tried to fight back and it still has a very minor presence in the tank - but it's for the most part under control. I'm happy with my tank again, my water is pristine and I've gradually added new livestock and all are doing really well - one thing I noticed, my sand sifting goby wouldn't touch the sand with this stuff on - blow it off gently with a turkey baster and he goes to work and I think being able to encourage him to keep busy with the sand has been the clincher in getting rid of this 'whatever the hell it is'. After a long chat at my LFS we've concluded that it MUST be a rare type of dino because to this day any turbo snail I introduce to the tank is dead within 48 hours - and only certain types of dino (not stringy or with air bubbles in this case) are toxic to specific species of snails. My nassarius are all fine, trochus doing well....it's just turbos. Anyway - I think I beat it. Try the silicate remover, run carbon sponge or activated carbon, keep nutrients low and make sure your whites aren't on for more than 4 hours with 2 hours blue either end. (mine were actually on for nearly double that and must have had an impact as this stuff is photosynthetic)
